User Contributed Notes 9 notes

Interactive Shell and Interactive Mode are not the same thing, despite the similar names and functionality.

If you type 'php -a' and get a response of 'Interactive Shell' followed by a 'php>' prompt, you have interactive shell available (PHP was compiled with readline support). If instead you get a response of 'Interactive mode enabled', you DO NOT have interactive shell available and this article does not apply to you.

You can also check 'php -m' and see if readline is listed in the output - if not, you don't have interactive shell.

Interactive mode is essentially like running php with stdin as the file input. You just type code, and when you're done (Ctrl-D), php executes whatever you typed as if it were a normal PHP (PHTML) file - hence you start in interactive mode with '<?php' in order to execute code.

Interactive shell evaluates every expression as you complete it (with ; or }), reports errors without terminating execution, and supports standard shell functionality via readline (history, tab completion, etc). It's an enhanced version of interactive mode that is ONLY available if you have the required libraries, and is an actual PHP shell that interprets everything you type as PHP code - using '<?php' will cause a parse error.

Finally, if you're running on Windows, you're probably screwed. From what I'm seeing in other comments here, you don't have readline, and without readline there is no interactive shell.

1) Hitting return does literally mean "execute this command". Semicolon to note end of line is still required. Meaning, doing the following will produce a parse error:

php > print "test"php > print "asdf";

Whereas doing the following is just fine:

php > print "test"php > ."asdf";

2) Fatal errors may eject you from the shell:

name@local:~$ php -aphp > asdf();

Fatal Error: call to undefined function...name@local:~$

3) User defined functions are not saved in history from shell session to shell session.

4) Should be obvious, but to quit the shell, just type "quit" at the php prompt.

5) In a sense, the shell interaction can be thought of as linearly following a regular php file, except it's live and dynamic. If you define a function that you've already defined earlier in your current shell, you will receive a fatal "function already defined" error only upon entering that closing bracket. And, although "including" a toolset of custom functions or a couple of script addon php files is rather handy, should you edit those files and wish to "reinclude" it again, you'll cause a fatal "function x already defined" error.

If you've ever wanted to build your own interactive shell, I released a project recently that makes it insanely easy to build awesome shell apps in PHP. It blends features from Zend2 and Symonfy2 with things like regex routing, state management, etc. Check it out here:

It seems the interactive shell cannot be made to work in WIN environments at the moment.

Using "php://stdin", it shouldn't be too difficult to roll your own. You can partially mimic the shell by calling this simple script (Note: Window's cmd already has an input history calling feature using the up/down keys, and that functionality will still be available during execution here):

Replace 'eval' with code to parse the input string, validate it using is_callable and other variable handling functions, catch fatal errors before they happen, allow line-by-line function defining, etc. Though Readline is not available in Windows, for more tips and examples for workarounds, see http://www.php.net/manual/en/ref.readline.php

I use git-bash in windows to connect to my servers via SSH. When I use the interactive mode via 'php -a' command I have to hit ctrl+d twice to execute the entered code. Example:(<ctrl+d> denotes hitting ctrl & D)